An active hydrocarbon system is defined by the presence of a porous reservoir formation that provides storage space for hydrocarbons, a seal that prevents hydrocarbons from escaping the reservoir, a good trapping geometry, and a source formation that contains a high percentage of biogenic material. Under the influence of high temperature and increased pressure, the biogenic material is matured (or cooked) to form hydrocarbons including gas, crude oil, asphalts and tar. Driven by buoyancy and pressure differentials, the hydrocarbons migrate and a fraction of those hydrocarbons accumulates in traps formed by fortuitous geometric arrangements of reservoir formations (i.e., trapping geometries) and seals. Traps have a finite volume, however, and may spill or leak some of the accumulated hydrocarbons, a portion of which may then collect in other traps.
Seismic images of the subsurface allow interpreters to identify some potential traps based on practice and suggestive geometries. At times, the seismic data may provide a direct indication for the presence of hydrocarbons. The standard interpretation practices, however, are labor intensive and often focused on areas where the interpreter gleans some indication of prospectivity. Many opportunities, therefore, remain undetected because the indications are too subtle or hidden, for example by seismic noise. Even if hints of prospectivity are observed, they may not be examined when in the presence of more obvious opportunities or when the interpreter is limited by time constraints. Thus, some hydrocarbon accumulations are discovered late or remain undiscovered.
Published attempts to solve similar problems include the following:    “Method for Seismic Interpretation Using Seismic Texture Attributes” (PCT Patent Application Publication WO 2010/053618) by Imhof discloses a method for the computation of texture attributes that may be used for classification and segmentation of seismic data based on their local appearance. Texture can be used to define seismic facies.    “Windowed Statistical Analysis for Anomaly Detection in Geophysical Datasets” (PCT Patent Application Publication WO 2010/056424) by Kumaran et al. discloses a method to examine seismic data for regions that are statistically anomalous in the context of the data and thus serves to highlight statistically unusual or salient areas.    “Method For Geophysical and Geological Interpretation of Seismic Volumes In Depth, Time, and Age” (U.S. Patent Application Publication No. 2010/0149917) by Imhof et al. discloses a method for the transformation of seismic data from the geophysical domains of depth or two-way travel time to a domain of geological age where all seismic reflections are approximately horizontal and comparable to their state at the geologic time of their formation. Seismic attributes formed from this age domain can improve definition of hydrocarbon system elements.    European Patent EP1110103 B1 (“Method Of Seismic Signal Processing”) to Meldahl et al. discloses a method for finding areas in seismic data that are similar to areas specified by the interpreter. Furthermore, it discloses the use of this method for finding seismic indications of percolating hydrocarbons.    U.S. Pat. No. 6,226,596 B1 (“Method for analyzing and classifying three dimensional seismic information”) to Gao discloses a method to generate seismic texture attributes that can be used for segmentation, classification, or the definition of seismic facies.    U.S. Pat. No. 6,438,493 B1 (“Method for seismic facies interpretation using textural analysis and neural networks”) to West and May discloses a method to generate seismic texture attributes that are used in a supervised classification to assign seismic facies attributes.    U.S. Pat. No. 6,516,274 B2 (“Method for imaging discontinuities in seismic data using dip-steering”) to Cheng et al. discloses a method for the detection of edges or discontinuities in seismic data that often indicate faults disrupting and displacing the regular layering in the subsurface.    U.S. Pat. No. 6,725,174 B2 (“Edge-preserving enhancement of seismic images by nonlinear anisotropic diffusion”) to Bouts et al. discloses a seismic data processing method that enhances seismic data by removal of incoherent noise while preserving sharp discontinuities corresponding to faults or rapid stratigraphic transitions such as entrenched channels.    U.S. Pat. No. 6,850,845 B2 (“System for multi-dimensional data analysis”) to Stark discloses a method of seismic data processing that allows computation of a geologic time attribute used for flattening and associated derivatory attributes.    U.S. Pat. No. 6,850,864 B2 (“Method for analyzing dip in seismic data volumes”) to Gillard et al. discloses a seismic data processing method for the estimation of reflection dips that define the local structure.    U.S. Pat. No. 7,203,342 B2 (“Image feature extraction”) to Pedersen discloses a seismic data processing method to detect and improve faults or horizons in relatively noisy data.    U.S. Pat. No. 7,424,367 B2 (“Method for predicting lithology and porosity from seismic reflection data”) to Saltzer et al. discloses a method for predicting lithology and porosity of subsurface rocks from seismic data and thus allows differentiation between reservoir rocks and sealing formations.    U.S. Pat. No. 7,454,292 B2 (“Inverse-vector method for smoothing dips and azimuths”) to Wang et al. discloses a method for the robust computation of horizon dips and orientations that define local structure.    PCT Patent Application Publication WO 2009/011735 (“Geologic Features From Curvelet Based Seismic Attributes”) by Neelamani and Converse discloses a method for the computation of hydrocarbon indicators or texture attributes that may be used for the identification of subsurface features.    PCT Patent Application Publication WO 2009/082545 A1 (“Detection Of Features In Seismic Images”) by Kumaran and Wang discloses a method for the detection of faults, channels, and similar features in seismic data.    PCT Patent Application Publication WO 2009/137150 A1 (“Method For Geophysical And Stratigraphic Interpretation Using Waveform Anomalies”) by Imhof discloses a seismic data processing method to map stratigraphic terminations and pinch outs.    PCT Patent Application Publication WO 2009/137228 A2 (“Transport Property Data Calculated From Derivative Seismic Rock Property Data For Transport Modeling”) by Oppert et al. discloses a method to estimate properties such as heat flow or fluid permeability that affect elements of the hydrocarbon system.    PCT Patent Application Publication WO2009/142872 A (“Seismic Horizon Skeletonization”) by Imhof et al. discloses an automatic method to extract a large number of horizons from a seismic dataset. Moreover, it discloses a broad pattern recognition workflow that partitions a dataset, analyzes the regions, and ranks them according to their potential of containing hydrocarbons.    “A New Class of Large-scale Attributes for Seismic Stratigraphy”, by Gesbert et al., 71st. EAGE Conference & Exhibition, (2009) discloses a set of stratigraphic attributes computed from two-dimensional seismic data that highlight regional unconformities and regional thinning trends and quantify regional seismic facies trends.    “Applications of plane-wave destruction filters” by Fomel, Geophysics 67, 1946-1960, (2002) discloses a method to estimate seismic horizon dip and orientation which define the local structure.    “Estimating Seismic Heterogeneity with the Structure Tensor” by Imhof, 67th EAGE Conference & Exhibition, (2005) discloses a method to estimate seismic horizon dip and orientation that define local structure and seismic texture attributes that characterize local heterogeneity.    “Flattening without picking” by Lomask et al., Geophysics 71, P13-P20 (2006) discloses a method of processing seismic data to approximately flatten the data which allows characterization of some elements of the hydrocarbon system.    “Hydrocarbon leakage interpreted on seismic data” by Løseth et al., Marine and Petroleum Geology 26, 1304-1319, (2009) discloses interpreter-driven methods for detection of hydrocarbons seeping through the subsurface.    “Hydrocarbon Traps, K. T. Biddle and C. C. Wielchowsky, The Petroleum System—From Source to Trap, AAPG Memoir 60, pages 219-235, (1994) presents a collection of hydrocarbon trap types.    “Imaging Vector Fields Using Line Integral Convolution” by Cabral and Leedom, Proceedings of ACM SigGraph 93, 263-270, (1993) discloses a method of visualizing vector fields of flowlines.    “Lithofacies Prediction in Deep Water Water Reservoirs” by Oppert et al., Society of Exploration Geophysicists, Expanded Abstracts, 1708-1711, (2006) discloses a method to estimate the lithology of the subsurface using seismic and wireline data.    “Seismic Rock-Property Inversion and Lithofacies Prediction at Erha Field, Nigeria” by Xu et al., Nigerian Association of Petroleum Explorationists (NAPE) 2008 conference proceedings, discloses a method to estimate the lithology of the subsurface using seismic and wireline data.    Randen and Sonneland (“Atlas of 3D Seismic Attributes”, in Mathematical Methods and Modeling in Hydrocarbon Exploration and Production, Iske and Randen (editors), Springer, pages 23-46 (2005)) present an overview of three-dimensional seismic attributes that characterize seismic texture or seismo-stratigraphic features.
What is needed is an automated system that scans an entire dataset for the elements of a hydrocarbon system and outputs a list of prospects for the interpreter to examine. Preferably, this list of potential targets is ranked by expected volume, presence and quality of hydrocarbon system elements, and confidence in their detection and identification. Preferably, the list of prospects is also annotated. The present invention satisfies at least these requirements.